#include "stdafx.h"
#include "MD5Checksum.h"
#include "MD5ChecksumDefines.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif


/*****************************************************************************************

*****************************************************************************************/
CString CMD5Checksum::GetMD5(CFile& File)
{
 try
 { 
  CMD5Checksum MD5Checksum;   //checksum object 
  int nLength = 0;       //number of bytes read from the file
  const int nBufferSize = 1024; //checksum the file in blocks of 1024 bytes
  BYTE Buffer[nBufferSize];   //buffer for data read from the file

  //checksum the file in blocks of 1024 bytes
  while ((nLength = File.Read( Buffer, nBufferSize )) > 0 )
  { 
   MD5Checksum.Update( Buffer, nLength );
  }
  
  //finalise the checksum and return it
  return MD5Checksum.Final();
 }

 //report any file exceptions in debug mode only
 catch (CFileException* e )
 { 
  TRACE0("CMD5Checksum::GetMD5: CFileException caught"); 
  throw e;
 }
}

/*****************************************************************************************
FUNCTION:  CMD5Checksum::RotateLeft
DETAILS:  private
DESCRIPTION: Rotates the bits in a 32 bit DWORD left by a specified amount
RETURNS:  The rotated DWORD
ARGUMENTS:  DWORD x : the value to be rotated
    int n   : the number of bits to rotate by
*****************************************************************************************/
DWORD CMD5Checksum::RotateLeft(DWORD x, int n)
{ 
 //check that DWORD is 4 bytes long - true in Visual C++ 6 and 32 bit Windows
 ASSERT( sizeof(x) == 4 );

 //rotate and return x
 return (x << n) | (x >> (32-n));
}


/*****************************************************************************************
FUNCTION:  CMD5Checksum::FF
DETAILS:  protected
DESCRIPTION: Implementation of basic MD5 transformation algorithm
RETURNS:  none
ARGUMENTS:  DWORD &A, B, C, D : Current (partial) checksum
    DWORD X           : Input data
    DWORD S     : MD5_SXX Transformation constant
    DWORD T     : MD5_TXX Transformation constant
NOTES:   None
*****************************************************************************************/
void CMD5Checksum::FF( DWORD& A, DWORD B, DWORD C, DWORD D, DWORD X, DWORD S, DWORD T)
{ 
 DWORD F = (B & C) | (~B & D);
 A += F + X + T;
 A = RotateLeft(A, S);
 A += B;
}


/*****************************************************************************************
FUNCTION:  CMD5Checksum::GG
DETAILS:  protected
DESCRIPTION: Implementation of basic MD5 transformation algorithm
RETURNS:  none
ARGUMENTS:  DWORD &A, B, C, D : Current (partial) checksum
    DWORD X           : Input data
    DWORD S      : MD5_SXX Transformation constant
    DWORD T      : MD5_TXX Transformation constant
NOTES:   None
*****************************************************************************************/
void CMD5Checksum::GG( DWORD& A, DWORD B, DWORD C, DWORD D, DWORD X, DWORD S, DWORD T)
{ 
 DWORD G = (B & D) | (C & ~D);
 A += G + X + T;
 A = RotateLeft(A, S);
 A += B;
}


/*****************************************************************************************
FUNCTION:  CMD5Checksum::HH
DETAILS:  protected
DESCRIPTION: Implementation of basic MD5 transformation algorithm
RETURNS:  none
ARGUMENTS:  DWORD &A, B, C, D : Current (partial) checksum
    DWORD X           : Input data
    DWORD S      : MD5_SXX Transformation constant
    DWORD T      : MD5_TXX Transformation constant
NOTES:   None
*****************************************************************************************/
void CMD5Checksum::HH( DWORD& A, DWORD B, DWORD C, DWORD D, DWORD X, DWORD S, DWORD T)
{ 
 DWORD H = (B ^ C ^ D);
 A += H + X + T;
 A = RotateLeft(A, S);
 A += B;
}


/*****************************************************************************************
FUNCTION:  CMD5Checksum::II
DETAILS:  protected
DESCRIPTION: Implementation of basic MD5 transformation algorithm
RETURNS:  none
ARGUMENTS:  DWORD &A, B, C, D : Current (partial) checksum
    DWORD X           : Input data
    DWORD S      : MD5_SXX Transformation constant
    DWORD T      : MD5_TXX Transformation constant
NOTES:   None
*****************************************************************************************/
void CMD5Checksum::II( DWORD& A, DWORD B, DWORD C, DWORD D, DWORD X, DWORD S, DWORD T)
{ 
 DWORD I = (C ^ (B | ~D));
 A += I + X + T;
 A = RotateLeft(A, S);
 A += B;
}


/*****************************************************************************************
FUNCTION:  CMD5Checksum::ByteToDWord
DETAILS:  private
DESCRIPTION: Transfers the data in an 8 bit array to a 32 bit array
RETURNS:  void
ARGUMENTS:  DWORD* Output : the 32 bit (unsigned long) destination array
    BYTE* Input   : the 8 bit (unsigned char) source array
    UINT nLength  : the number of 8 bit data items in the source array
NOTES:   Four BYTES from the input array are transferred to each DWORD entry
    of the output array. The first BYTE is transferred to the bits (0-7)
    of the output DWORD, the second BYTE to bits 8-15 etc.
    The algorithm assumes that the input array is a multiple of 4 bytes long
    so that there is a perfect fit into the array of 32 bit words.
*****************************************************************************************/
void CMD5Checksum::ByteToDWord(DWORD* Output, BYTE* Input, UINT nLength)
{ 
 //entry invariants
 ASSERT( nLength % 4 == 0 );
 ASSERT( AfxIsValidAddress(Output, nLength/4, TRUE) );
 ASSERT( AfxIsValidAddress(Input, nLength, FALSE) );

 //initialisations
 UINT i=0; //index to Output array
 UINT j=0; //index to Input array

 //transfer the data by shifting and copying
 for ( ; j < nLength; i++, j += 4)
 { 
  Output[i] = (ULONG)Input[j]   |
     (ULONG)Input[j+1] << 8 |
     (ULONG)Input[j+2] << 16 |
     (ULONG)Input[j+3] << 24;
 }
}

/*****************************************************************************************
FUNCTION:  CMD5Checksum::Transform
DETAILS:  protected
DESCRIPTION: MD5 basic transformation algorithm;  transforms 'm_lMD5'
RETURNS:  void
ARGUMENTS:  BYTE Block[64]
NOTES:   An MD5 checksum is calculated by four rounds of 'Transformation'.
    The MD5 checksum currently held in m_lMD5 is merged by the
    transformation process with data passed in 'Block'. 
*****************************************************************************************/
void CMD5Checksum::Transform(BYTE Block[64])
{ 
 //initialise local data with current checksum
 ULONG a = m_lMD5[0];
 ULONG b = m_lMD5[1];
 ULONG c = m_lMD5[2];
 ULONG d = m_lMD5[3];

 //copy BYTES from input 'Block' to an array of ULONGS 'X'
 ULONG X[16];
 ByteToDWord( X, Block, 64 );

 //Perform Round 1 of the transformation
 FF (a, b, c, d, X[ 0], MD5_S11, MD5_T01);
 FF (d, a, b, c, X[ 1], MD5_S12, MD5_T02);
 FF (c, d, a, b, X[ 2], MD5_S13, MD5_T03);
 FF (b, c, d, a, X[ 3], MD5_S14, MD5_T04);
 FF (a, b, c, d, X[ 4], MD5_S11, MD5_T05);
 FF (d, a, b, c, X[ 5], MD5_S12, MD5_T06);
 FF (c, d, a, b, X[ 6], MD5_S13, MD5_T07);
 FF (b, c, d, a, X[ 7], MD5_S14, MD5_T08);
 FF (a, b, c, d, X[ 8], MD5_S11, MD5_T09);
 FF (d, a, b, c, X[ 9], MD5_S12, MD5_T10);
 FF (c, d, a, b, X[10], MD5_S13, MD5_T11);
 FF (b, c, d, a, X[11], MD5_S14, MD5_T12);
 FF (a, b, c, d, X[12], MD5_S11, MD5_T13);
 FF (d, a, b, c, X[13], MD5_S12, MD5_T14);
 FF (c, d, a, b, X[14], MD5_S13, MD5_T15);
 FF (b, c, d, a, X[15], MD5_S14, MD5_T16);

 //Perform Round 2 of the transformation
 GG (a, b, c, d, X[ 1], MD5_S21, MD5_T17);
 GG (d, a, b, c, X[ 6], MD5_S22, MD5_T18);
 GG (c, d, a, b, X[11], MD5_S23, MD5_T19);
 GG (b, c, d, a, X[ 0], MD5_S24, MD5_T20);
 GG (a, b, c, d, X[ 5], MD5_S21, MD5_T21);
 GG (d, a, b, c, X[10], MD5_S22, MD5_T22);
 GG (c, d, a, b, X[15], MD5_S23, MD5_T23);
 GG (b, c, d, a, X[ 4], MD5_S24, MD5_T24);
 GG (a, b, c, d, X[ 9], MD5_S21, MD5_T25);
 GG (d, a, b, c, X[14], MD5_S22, MD5_T26);
 GG (c, d, a, b, X[ 3], MD5_S23, MD5_T27);
 GG (b, c, d, a, X[ 8], MD5_S24, MD5_T28);
 GG (a, b, c, d, X[13], MD5_S21, MD5_T29);
 GG (d, a, b, c, X[ 2], MD5_S22, MD5_T30);
 GG (c, d, a, b, X[ 7], MD5_S23, MD5_T31);
 GG (b, c, d, a, X[12], MD5_S24, MD5_T32);

 //Perform Round 3 of the transformation
 HH (a, b, c, d, X[ 5], MD5_S31, MD5_T33);
 HH (d, a, b, c, X[ 8], MD5_S32, MD5_T34);
 HH (c, d, a, b, X[11], MD5_S33, MD5_T35);
 HH (b, c, d, a, X[14], MD5_S34, MD5_T36);
 HH (a, b, c, d, X[ 1], MD5_S31, MD5_T37);
 HH (d, a, b, c, X[ 4], MD5_S32, MD5_T38);
 HH (c, d, a, b, X[ 7], MD5_S33, MD5_T39);
 HH (b, c, d, a, X[10], MD5_S34, MD5_T40);
 HH (a, b, c, d, X[13], MD5_S31, MD5_T41);
 HH (d, a, b, c, X[ 0], MD5_S32, MD5_T42);
 HH (c, d, a, b, X[ 3], MD5_S33, MD5_T43);
 HH (b, c, d, a, X[ 6], MD5_S34, MD5_T44);
 HH (a, b, c, d, X[ 9], MD5_S31, MD5_T45);
 HH (d, a, b, c, X[12], MD5_S32, MD5_T46);
 HH (c, d, a, b, X[15], MD5_S33, MD5_T47);
 HH (b, c, d, a, X[ 2], MD5_S34, MD5_T48);

 //Perform Round 4 of the transformation
 II (a, b, c, d, X[ 0], MD5_S41, MD5_T49);
 II (d, a, b, c, X[ 7], MD5_S42, MD5_T50);
 II (c, d, a, b, X[14], MD5_S43, MD5_T51);
 II (b, c, d, a, X[ 5], MD5_S44, MD5_T52);
 II (a, b, c, d, X[12], MD5_S41, MD5_T53);
 II (d, a, b, c, X[ 3], MD5_S42, MD5_T54);
 II (c, d, a, b, X[10], MD5_S43, MD5_T55);
 II (b, c, d, a, X[ 1], MD5_S44, MD5_T56);
 II (a, b, c, d, X[ 8], MD5_S41, MD5_T57);
 II (d, a, b, c, X[15], MD5_S42, MD5_T58);
 II (c, d, a, b, X[ 6], MD5_S43, MD5_T59);
 II (b, c, d, a, X[13], MD5_S44, MD5_T60);
 II (a, b, c, d, X[ 4], MD5_S41, MD5_T61);
 II (d, a, b, c, X[11], MD5_S42, MD5_T62);
 II (c, d, a, b, X[ 2], MD5_S43, MD5_T63);
 II (b, c, d, a, X[ 9], MD5_S44, MD5_T64);

 //add the transformed values to the current checksum
 m_lMD5[0] += a;
 m_lMD5[1] += b;
 m_lMD5[2] += c;
 m_lMD5[3] += d;
}


/*****************************************************************************************
CONSTRUCTOR: CMD5Checksum
DESCRIPTION: Initialises member data
ARGUMENTS:  None
NOTES:   None
*****************************************************************************************/
CMD5Checksum::CMD5Checksum()
{ 
 // zero members
 memset( m_lpszBuffer, 0, 64 );
 m_nCount[0] = m_nCount[1] = 0;

 // Load magic state initialization constants
 m_lMD5[0] = MD5_INIT_STATE_0;
 m_lMD5[1] = MD5_INIT_STATE_1;
 m_lMD5[2] = MD5_INIT_STATE_2;
 m_lMD5[3] = MD5_INIT_STATE_3;
}

/*****************************************************************************************
FUNCTION:  CMD5Checksum::DWordToByte
DETAILS:  private
DESCRIPTION: Transfers the data in an 32 bit array to a 8 bit array
RETURNS:  void
ARGUMENTS:  BYTE* Output  : the 8 bit destination array
   DWORD* Input  : the 32 bit source array
   UINT nLength  : the number of 8 bit data items in the source array
NOTES:   One DWORD from the input array is transferred into four BYTES
   in the output array. The first (0-7) bits of the first DWORD are
   transferred to the first output BYTE, bits bits 8-15 are transferred from
   the second BYTE etc.
   
   The algorithm assumes that the output array is a multiple of 4 bytes long
   so that there is a perfect fit of 8 bit BYTES into the 32 bit DWORDs.
*****************************************************************************************/
void CMD5Checksum::DWordToByte(BYTE* Output, DWORD* Input, UINT nLength )
{ 
 //entry invariants
 ASSERT( nLength % 4 == 0 );
 ASSERT( AfxIsValidAddress(Output, nLength, TRUE) );
 ASSERT( AfxIsValidAddress(Input, nLength/4, FALSE) );

 //transfer the data by shifting and copying
 UINT i = 0;
 UINT j = 0;
 for ( ; j < nLength; i++, j += 4)
 { 
  Output[j]  = (UCHAR)(Input[i] & 0xff    );
  Output[j+1] = (UCHAR)((Input[i] >> 8) & 0xff);
  Output[j+2] = (UCHAR)((Input[i] >> 16) & 0xff);
  Output[j+3] = (UCHAR)((Input[i] >> 24) & 0xff);
 }
}


/*****************************************************************************************
FUNCTION:  CMD5Checksum::Final
DETAILS:  protected
DESCRIPTION: Implementation of main MD5 checksum algorithm; ends the checksum calculation.
RETURNS:  CString : the final hexadecimal MD5 checksum result
ARGUMENTS:  None
NOTES:   Performs the final MD5 checksum calculation ('Update' does most of the work,
    this function just finishes the calculation.)
*****************************************************************************************/
CString CMD5Checksum::Final()
{ 
 //Save number of bits
 BYTE Bits[8];
 DWordToByte( Bits, m_nCount, 8 );

 //Pad out to 56 mod 64.
 UINT nIndex = (UINT)((m_nCount[0] >> 3) & 0x3f);
 UINT nPadLen = (nIndex < 56) ? (56 - nIndex) : (120 - nIndex);
 Update( PADDING, nPadLen );

 //Append length (before padding)
 Update( Bits, 8 );

 //Store final state in 'lpszMD5'
 const int nMD5Size = 16;
 unsigned char lpszMD5[ nMD5Size ];
 DWordToByte( lpszMD5, m_lMD5, nMD5Size );

 //Convert the hexadecimal checksum to a CString
 CString strMD5;
 for ( int i=0; i < nMD5Size; i++)
 { 
  CStringA Str;
  if (lpszMD5[i] == 0)
  { 
   Str = CString("00");
  }
  else if (lpszMD5[i] <= 15)  
  { 
   Str.Format("0%x",lpszMD5[i]);
  }
  else
  { 
   Str.Format("%x",lpszMD5[i]);
  }

  ASSERT( Str.GetLength() == 2 );
  strMD5 += Str;
 }
 ASSERT( strMD5.GetLength() == 32 );
 return strMD5;
}


/*****************************************************************************************
FUNCTION:  CMD5Checksum::Update
DETAILS:  protected
DESCRIPTION: Implementation of main MD5 checksum algorithm
RETURNS:  void
ARGUMENTS:  BYTE* Input    : input block
   UINT nInputLen : length of input block
NOTES:   Computes the partial MD5 checksum for 'nInputLen' bytes of data in 'Input'
*****************************************************************************************/
void CMD5Checksum::Update( BYTE* Input, ULONG nInputLen )
{ 
 //Compute number of bytes mod 64
 UINT nIndex = (UINT)((m_nCount[0] >> 3) & 0x3F);

 //Update number of bits
 if ( ( m_nCount[0] += nInputLen << 3 )  <  ( nInputLen << 3) )
 { 
  m_nCount[1]++;
 }
 m_nCount[1] += (nInputLen >> 29);

 //Transform as many times as possible.
 UINT i=0;  
 UINT nPartLen = 64 - nIndex;
 if (nInputLen >= nPartLen)  
 { 
  memcpy( &m_lpszBuffer[nIndex], Input, nPartLen );
  Transform( m_lpszBuffer );
  for (i = nPartLen; i + 63 < nInputLen; i += 64)
  { 
   Transform( &Input[i] );
  }
  nIndex = 0;
 }
 else
 {
  i = 0;
 }

 // Buffer remaining input
 memcpy( &m_lpszBuffer[nIndex], &Input[i], nInputLen-i);
}

 

CString CMD5Checksum::GetMD5OfString(CString strString)
{
 try
 { 
  CMD5Checksum MD5Checksum;   //checksum object 
  int nLength = strString.GetLength();       //number of bytes read from the file
  //const int nBufferSize = 1024; //checksum the file in blocks of 1024 bytes
  BYTE *Buffer;   //buffer for data read from the file
  Buffer=(BYTE*)(strString.GetBuffer(nLength));
  //checksum the file in blocks of 1024 bytes
  //while ((nLength = File.Read( Buffer, nBufferSize )) > 0 )
  //{ 
   MD5Checksum.Update( Buffer, nLength );
  //}
  //finalise the checksum and return it
  return MD5Checksum.Final();
 }

 //report any file exceptions in debug mode only
 catch (CFileException* e )
 { 
  TRACE0("CMD5Checksum::GetMD5: CFileException caught"); 
  throw e;
 }
}

 

 

 

